1. Field of the Invention
The present invention relates to a cold air circulation device of a refrigerator, and more particularly to a cold air circulation device for a refrigerator, which is capable of completely circulating the cold air in the refrigerating and freezing compartments of the refrigerator such that the cold air circulates even portions of the refrigerating and freezing compartments respectively disposed near the door of the refrigerating and freezing compartments, thereby uniformly supplying the cold air to the refrigerating and freezing compartments.
2. Description of the Background Art
Referring to FIG. 1, the configuration of a conventional refrigerator is illustrated. A cold air circulation in such a conventional refrigerator will now be described in conjunction with FIG. 1.
As shown in FIG. 1, the interior of the conventional refrigerator is divided into a freezing compartment 10 for storing foods in a frozen state and a refrigerating compartment 20 for storing foods in a refrigerated state. A barrier 30 divides the refrigerator into the freezing and refrigerating compartments 10 and 20. A foamed thermal insulator material is filled between an outer casing 2 of the refrigerator and inner casings 4a and 4b defining the interior of the refrigerator in order to prevent the interior of the refrigerator from performing a heat exchange operation with the exterior of the refrigerator. An evaporator 6 is disposed in the rear portion of the freezing compartment 10. In the rear portion of the freezing compartment 10, a fan 8 is also disposed to supply cold air generated by the evaporator 6 to the freezing and refrigerating compartments 10 and 20. A freezing compartment return duct 19 and a refrigerating compartment return duct 29 are provided in the barrier 30 to return the cold air circulating through the freezing and refrigerating compartments 10 and 20 back to the evaporator 6, respectively.
In order to open and close the freezing and refrigerating compartments 10 and 20, a freezing compartment door 12 and a refrigerating compartment door 22 are mounted on the front ends of the freezing and refrigerating compartments 10 and 20, respectively. A plurality of door baskets 14 and 24 are provided at the inner surfaces of the freezing and refrigerating compartment doors 12 and 22, respectively, in order to receive foods to be stored. A plurality of shelves 16 and 26 are separably mounted in the freezing and refrigerating compartments 10 and 20, respectively, in order to lay foods to be stored thereon.
Cold air circulation paths provided in such a conventional refrigerator configuration will be described.
Cold air, which is generated by the evaporator 6 in a contact manner, is supplied to the freezing and refrigerating compartments 10 and 20 by the fan 8. Introduction of the cold air into the freezing compartment 10 is carried out through a plurality of cold air inlets 18a formed at a grill 18 defining the rear surface of the freezing compartment 10. The cold air inlets 18a include upper cold air inlets 18ab open to an upper portion of the freezing compartment 10 formed above the freezing compartment shelf 16, and lower cold air inlets 18ac open to a lower portion of the freezing compartment 10 formed beneath the freezing compartment shelf 16.
The cold air introduced into the freezing compartment 10 through the cold air inlets 18a performs a heat exchange operation with the foods stored in the freezing compartment 10 while circulating the interior of the freezing compartment 10. As a result, the temperature of the circulating cold air increases to a relatively high temperature. The circulated air with the relatively high temperature then returns to the evaporator 6 via the freezing compartment return duct 19 having an inlet at the lower surface of the freezing compartment 10, in particular, near the freezing compartment door 12. This flow of cold air in the freezing compartment 10 is indicated by arrow in FIG. 1.
The above-described conventional cold air circulation configuration, however, has various drawbacks as follows.
As mentioned above, the cold air supplied from the evaporator 6 to the interior of the freezing compartment 10 flows back to the evaporator 6 via the freezing compartment return duct 19 having an inlet at the lower surface of the freezing compartment 10 near the freezing compartment door 12. However, the cold air does not flow through the freezing compartment door baskets 14 mounted to the inner surface of the freezing compartment door 12. In other words, the conventional cold air circulation configuration has a drawback in that an insufficient flow of cold air is provided at a portion of the freezing compartment 10 where the freezing compartment door baskets 14 are arranged, even though that portion of the freezing compartment 10 is first exposed to the ambient air of a relatively high temperature when the freezing compartment door 12 is opened.
Furthermore, since the inlet of the freezing compartment return duct 19 is arranged at the lower surface of the freezing compartment 10 near the freezing compartment door 12, it is impossible to provide a sufficient flow of cold air to the portion of the freezing compartment 10 facing the inlet of the freezing compartment return duct 19, i.e., to the upper portion 10a of the freezing compartment 10 (the dotted portion in FIG. 1) adjacent to the freezing compartment door 12.
The fact that the freezing compartment 10 includes the upper portion 10a or the like where an insufficient flow of cold air is provided indicates that the cold air is non-uniformly circulated throughout the entire freezing compartment 10. As a result, it is extremely difficult, if not impossible, to maintain a uniform freezing temperature throughout the entire freezing compartment 10. Consequently, foods stored in the freezing compartment 10 may spoil due to a temperature variation occurring within the freezing compartment 10.
In order to solve the above-described and other problems encountered in the conventional refrigerator, a technique has been proposed in which cold air ports are provided at the lower surface of each door basket mounted in the freezing compartment. However, the proposed configuration does not adequately address the problems. Although the cold air ports are provided at the lower surface of each door basket, they may be blocked by foods received in the door basket. For this reason, such cold air ports function insufficiently to remedy the problems. Furthermore, such cold air ports do not supply sufficient cold air to the upper portion 10a of the freezing compartment 10 disposed near the freezing compartment door 12.
The configuration of the refrigerating compartment 20 and a cold air circulation performed in the refrigerating compartment 20 will be described.
The cold air generated in accordance with the heat exchange operation of the evaporator 6 is partially guided to a refrigerating compartment duct 28 via a space defined between the grill 18 and a shroud 9 arranged in the rear portion of the grill 18. The cold air introduced in the refrigerating compartment duct 28 is then supplied to the refrigerating compartment 20 through a plurality of cold air inlets 28a formed at the front surface of the refrigerating compartment duct 28. The cold air inlets 28a are arranged such that they are open to different portions of the refrigerating compartment 20 partitioned by the shelves 26, respectively. The cold air supplied to the refrigerating compartment 20 performs a heat exchange operation with the foods stored in the refrigerating compartment 20 while circulating in the interior of the refrigerating compartment 20. As a result, the temperature of the circulating cold air increases to a relatively high temperature. The circulating air with the relatively high temperature then returns to the evaporator 6 via the refrigerating compartment return duct 29 having an inlet at the upper surface of the refrigerating compartment 20 near the refrigerating compartment door 22.
However, the above-mentioned cold air circulation configuration associated with the refrigerating compartment 20 has drawbacks similar to those involved in the cold air circulation configuration associated with the freezing compartment 10.
In the refrigerating compartment 20, an insufficient flow of cold air is supplied to a portion of the refrigerating compartment 20 where the refrigerating compartment door baskets 24 are arranged. As a result, the temperature near the door basket portion of the refrigerating compartment 20 is maintained at a relatively high value as compared to other portions of the refrigerating compartment 20.
The refrigerating compartment 20 is frequently opened and closed, perhaps more than the freezing compartment 10. For this reason, an ambient air of high temperature can enter the refrigerating compartment 20 more frequently. Certain portions of the refrigerating compartment 20, where the door baskets 24 are disposed, are easily exposed to the high-temperature, ambient air. Accordingly, an increased amount of cold air need to be supplied to such door basket portions of the refrigerating compartment 20 to maintain a cool temperature.
Further, in the above-mentioned conventional configuration, a limited cold air circulation is obtained. Such a limited cold air circulation results in a difficulty in maintaining a set freezing or refrigerating temperature. Consequently, there is a major problem of spoiling foods stored in the refrigerator.